How old is my 13-B?

[bowjangles]

Here is a pic of the Mazda logo from my 13-B.Using the info and pics that you sent me the engine can't be a '74-76 because the word MAZDA is not in slanted script, right?
So, we are getting closer to finding out the age of this engine.Are we now sure that it was made from'76-78?

I just found a complicating factor. When I ordered a new manifold intake gasket from Racing Beat Inc. I matched up fotos of available gaskets with my old gasket and it matched perfectly with #of a gasket that fit a '74-75 13B. Now I'm, really confused.......What year can the engine be?